1. Field of the Invention
The present invention relates to apparatus for accessing, from a remote source, data defining a graphical representation of a virtual environment, with the user being enabled to navigate by selecting and controllably altering a viewpoint within the virtual environment, the apparatus having means for rendering a display of the virtual environment from that viewpoint.
2. Description of the Related Art
A description of a service providing a virtual environment (or cyber-space) accessible by remote users is given in European Patent Application No. EP-A-0 697 613, corresponding to U.S. Pat. No. 6,085,256 (Sony Corp.). The system described includes a server providing a virtual reality space, and user terminals connected to the server via a high-speed communications network (using optical fibers or the like). In operation, the server maintains a number of virtual environments and supports many differing terminal types by the use of conversion objects between information objects and user objects, i.e., the conversion objects provide individually tailored translation for communications back and forth between each type of terminal and each configuration of virtual environment supported. A particular benefit arises when the format of data storage and representation for virtual environments is at least partially standardized, allowing for greater interchange between systems of different manufacturers as well as a reduction in the necessity for individually tailored translation utilities. With at least partial standardization, the necessary configuration of a browser for accessing such data, whether in hardware or software implementation or a mixture of the two, becomes simpler.
A notable example of standardization in the field of data-defining virtual environments is the so-called Virtual Reality Modelling Language (VRML) as described, for example, in the VRML standard, version 2.0, issued as ISO/IEC WD14772 on Aug. 4, 1996. VRML is a file format for describing interactive three-dimensional objects and worlds to be experienced on the Internet/World Wide Web and it is generally analogous to the way HTML (HyperText Markup Language) is used to describe documents for transmission over the Internet. A number of examples of VRML browsers are discussed in “Building VRML Worlds” by E. Tittel et al., published by McGraw Hill 1997, ISBN 0-07-882233-5, at pages 26 to 31. The functionalities of the different browsers depend, to a large extent, on their target host system and the likely uses of the same, as well as whether they are purpose-built/written or whether they are modifications of earlier utilities.
As the number of different systems providing virtual environments, and the number of different navigation and interaction techniques, increase coupled with the increasing number of users accessing such systems, a need has arisen for a means to allow inexperienced users to simply navigate virtual environments. The problem is one of perception coupled with expectation, i.e., even where the virtual environment is a close simulation of a real-world scenario, the inexperienced user may be put off by the process of learning a new way to navigate what should be a familiar situation. Because of the possibilities offered to the designer, many virtual environments present exotic and fantastic scenarios that even the experienced “virtual navigator” can find difficulty with at first.